tree-wide: suppress misc-use-internal-linkage warnings

Suppress warnings like the following from clang tidy:
```
../src/boot/addon.c:11:19: error: function 'efi_main' can be made static to enforce internal linkage [misc-use-internal-linkage,-warnings-as-errors]
   11 | EFIAPI EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *system_table);
      |                   ^
```

Some warnings are suppressed simply by setting comments to ignore the warning,
some are by making global variables static, or include a suitable header.

src/boot/addon.c

@@ -8,6 +8,7 @@ DECLARE_NOALLOC_SECTION(".sdmagic", "#### LoaderInfo: systemd-addon " GIT_VERSIO
 
 /* This is intended to carry data, not to be executed */
 
+// NOLINTNEXTLINE(misc-use-internal-linkage)
 EFIAPI EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *system_table);
 EFIAPI EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *system_table) {
         return EFI_UNSUPPORTED;

src/boot/boot.c

@@ -3255,4 +3255,5 @@ static EFI_STATUS run(EFI_HANDLE image) {
         }
 }
 
+// NOLINTNEXTLINE(misc-use-internal-linkage)
 DEFINE_EFI_MAIN_FUNCTION(run, "systemd-boot", /* wait_for_debugger= */ false);

src/boot/efi-log.c

@@ -132,6 +132,7 @@ void log_wait(void) {
         log_count = 0;
 }
 
+// NOLINTNEXTLINE(misc-use-internal-linkage)
 _used_ intptr_t __stack_chk_guard = (intptr_t) 0x70f6967de78acae3;
 
 /* We can only set a random stack canary if this function attribute is available,
@@ -147,8 +148,10 @@ void __stack_chk_guard_init(void) {
 }
 #endif
 
+// NOLINTBEGIN(misc-use-internal-linkage)
 _used_ _noreturn_ void __stack_chk_fail(void);
 _used_ _noreturn_ void __stack_chk_fail_local(void);
+// NOLINTEND(misc-use-internal-linkage)
 void __stack_chk_fail(void) {
         panic(u"systemd-boot: Stack check failed, halting.");
 }
@@ -157,6 +160,7 @@ void __stack_chk_fail_local(void) {
 }
 
 /* Called by libgcc for some fatal errors like integer overflow with -ftrapv. */
+// NOLINTNEXTLINE(misc-use-internal-linkage)
 _used_ _noreturn_ void abort(void);
 void abort(void) {
         panic(u"systemd-boot: Unknown error, halting.");
@@ -164,8 +168,10 @@ void abort(void) {
 
 #if defined(__ARM_EABI__)
 /* These override the (weak) div0 handlers from libgcc as they would otherwise call raise() instead. */
+// NOLINTBEGIN(misc-use-internal-linkage)
 _used_ _noreturn_ int __aeabi_idiv0(int return_value);
 _used_ _noreturn_ long long __aeabi_ldiv0(long long return_value);
+// NOLINTEND(misc-use-internal-linkage)
 
 int __aeabi_idiv0(int return_value) {
         panic(u"systemd-boot: Division by zero, halting.");

src/boot/efi-string.c

@@ -1050,10 +1050,12 @@ char16_t *xvasprintf_status(EFI_STATUS status, const char *format, va_list ap) {
 #  undef memcmp
 #  undef memcpy
 #  undef memset
+// NOLINTBEGIN(misc-use-internal-linkage)
 _used_ void *memchr(const void *p, int c, size_t n);
 _used_ int memcmp(const void *p1, const void *p2, size_t n);
 _used_ void *memcpy(void * restrict dest, const void * restrict src, size_t n);
 _used_ void *memset(void *p, int c, size_t n);
+// NOLINTEND(misc-use-internal-linkage)
 #else
 /* And for userspace unit testing we need to give them an efi_ prefix. */
 #  undef memchr

src/boot/generate-hwids-section.py

@@ -20,6 +20,7 @@ print(
 #include <stddef.h>
 #include <stdint.h>
 
+// NOLINTNEXTLINE(misc-use-internal-linkage)
 const uint8_t hwids_section_data[] = {
     """,
     end='',
@@ -34,6 +35,8 @@ for i, b in enumerate(hwids):
 
 print(
     """};
+
+// NOLINTNEXTLINE(misc-use-internal-linkage)
 const size_t hwids_section_len =""",
     f'{len(hwids)};',
 )

src/boot/stub.c

@@ -1325,4 +1325,5 @@ static EFI_STATUS run(EFI_HANDLE image) {
         return err;
 }
 
+// NOLINTNEXTLINE(misc-use-internal-linkage)
 DEFINE_EFI_MAIN_FUNCTION(run, "systemd-stub", /* wait_for_debugger= */ false);