bless-boot: avoid false maybe-uninitialized warning

Obserbed with GCC-11 on Ubuntu.
```
In file included from ../src/shared/format-table.h:7,
                 from ../src/bless-boot/bless-boot.c:11:
../src/bless-boot/bless-boot.c: In function ‘verb_set’:
../src/basic/log.h:187:27: error: ‘source2’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  187 |                         ? log_internal(_level, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
      |                           ^~~~~~~~~~~~
../src/bless-boot/bless-boot.c:458:40: note: ‘source2’ was declared here
  458 |         const char *target, *source1, *source2;
      |                                        ^~~~~~~
In file included from ../src/shared/format-table.h:7,
                 from ../src/bless-boot/bless-boot.c:11:
../src/basic/log.h:187:27: error: ‘source1’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  187 |                         ? log_internal(_level, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
      |                           ^~~~~~~~~~~~
../src/bless-boot/bless-boot.c:458:30: note: ‘source1’ was declared here
  458 |         const char *target, *source1, *source2;
      |                              ^~~~~~~
In file included from ../src/shared/format-table.h:7,
                 from ../src/bless-boot/bless-boot.c:11:
../src/basic/log.h:187:27: error: ‘target’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  187 |                         ? log_internal(_level, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
      |                           ^~~~~~~~~~~~
../src/bless-boot/bless-boot.c:458:21: note: ‘target’ was declared here
  458 |         const char *target, *source1, *source2;
      |                     ^~~~~~
cc1: all warnings being treated as errors
```

diff --git a/src/bless-boot/bless-boot.c b/src/bless-boot/bless-boot.c
index 43fb72cddb72b559661f3702edf3836f284cffcf..4242182ac10b42b3db5c855119fbff4a8a064d6f 100644 (file)
--- a/src/bless-boot/bless-boot.c
+++ b/src/bless-boot/bless-boot.c
@@ -455,7 +455,7 @@ VERB_FULL(verb_set, "indeterminate", NULL, VERB_ANY, 1, 0, STATUS_INDETERMINATE,
           "Undo any marking as good or bad");
 static int verb_set(int argc, char *argv[], uintptr_t data, void *userdata) {
         _cleanup_free_ char *path = NULL, *prefix = NULL, *suffix = NULL, *good = NULL, *bad = NULL;
-        const char *target, *source1, *source2;
+        const char *target = NULL, *source1 = NULL, *source2 = NULL;  /* avoid false maybe-uninitialized warning */
         uint64_t left, done;
         Status status = data;
         int r;