tree-wide: use -EBADF for fd initialization

-1 was used everywhere, but -EBADF or -EBADFD started being used in various
places. Let's make things consistent in the new style.

Note that there are two candidates:
EBADF 9 Bad file descriptor
EBADFD 77 File descriptor in bad state

Since we're initializating the fd, we're just assigning a value that means
"no fd yet", so it's just a bad file descriptor, and the first errno fits
better. If instead we had a valid file descriptor that became invalid because
of some operation or state change, the other errno would fit better.

In some places, initialization is dropped if unnecessary.

src/basic/random-util.c

@@ -75,7 +75,7 @@ static void fallback_random_bytes(void *p, size_t n) {
 
 void random_bytes(void *p, size_t n) {
         static bool have_getrandom = true, have_grndinsecure = true;
-        _cleanup_close_ int fd = -1;
+        _cleanup_close_ int fd = -EBADF;
 
         if (n == 0)
                 return;
@@ -117,7 +117,7 @@ void random_bytes(void *p, size_t n) {
 
 int crypto_random_bytes(void *p, size_t n) {
         static bool have_getrandom = true, seen_initialized = false;
-        _cleanup_close_ int fd = -1;
+        _cleanup_close_ int fd = -EBADF;
 
         if (n == 0)
                 return 0;
@@ -145,7 +145,7 @@ int crypto_random_bytes(void *p, size_t n) {
         }
 
         if (!seen_initialized) {
-                _cleanup_close_ int ready_fd = -1;
+                _cleanup_close_ int ready_fd = -EBADF;
                 int r;
 
                 ready_fd = open("/dev/random", O_RDONLY|O_CLOEXEC|O_NOCTTY);
@@ -187,7 +187,7 @@ size_t random_pool_size(void) {
 }
 
 int random_write_entropy(int fd, const void *seed, size_t size, bool credit) {
-        _cleanup_close_ int opened_fd = -1;
+        _cleanup_close_ int opened_fd = -EBADF;
         int r;
 
         assert(seed || size == 0);