tree-wide: drop !! casts to booleans

They are not needed, because anything that is non-zero is converted
to true.

C11:
> 6.3.1.2: When any scalar value is converted to _Bool, the result is 0 if the
> value compares equal to 0; otherwise, the result is 1.

https://stackoverflow.com/questions/31551888/casting-int-to-bool-in-c-c

src/basic/btrfs-util.c

@@ -500,7 +500,7 @@ int btrfs_subvol_get_info_fd(int fd, uint64_t subvol_id, BtrfsSubvolInfo *ret) {
                                 (usec_t) le32toh(ri->otime.nsec) / NSEC_PER_USEC;
 
                         ret->subvol_id = subvol_id;
-                        ret->read_only = !!(le64toh(ri->flags) & BTRFS_ROOT_SUBVOL_RDONLY);
+                        ret->read_only = le64toh(ri->flags) & BTRFS_ROOT_SUBVOL_RDONLY;
 
                         assert_cc(sizeof(ri->uuid) == sizeof(ret->uuid));
                         memcpy(&ret->uuid, ri->uuid, sizeof(ret->uuid));

src/basic/format-table.c

@@ -572,7 +572,7 @@ int table_add_many_internal(Table *t, TableDataType first_type, ...) {
                         break;
 
                 case TABLE_BOOLEAN:
-                        buffer.b = !!va_arg(ap, int);
+                        buffer.b = va_arg(ap, int);
                         data = &buffer.b;
                         break;
 

src/basic/verbs.c

@@ -81,7 +81,7 @@ int dispatch_verb(int argc, char *argv[], const Verb verbs[], void *userdata) {
                 if (name)
                         found = streq(name, verbs[i].verb);
                 else
-                        found = !!(verbs[i].flags & VERB_DEFAULT);
+                        found = verbs[i].flags & VERB_DEFAULT;
 
                 if (found) {
                         verb = &verbs[i];

src/basic/virt.c

@@ -56,7 +56,7 @@ static int detect_vm_cpuid(void) {
         if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) == 0)
                 return VIRTUALIZATION_NONE;
 
-        hypervisor = !!(ecx & 0x80000000U);
+        hypervisor = ecx & 0x80000000U;
 
         if (hypervisor) {
                 union {