virAsprintf: remove its warn_unused_result attribute

* src/util/util.h (virAsprintf): Remove ATTRIBUTE_RETURN_CHECK, since
it is perfectly fine to ignore the return value, now that the pointer
is guaranteed to be set to NULL upon failure.
* src/util/storage_file.c (absolutePathFromBaseFile): Remove now-
unnecessary use of ignore_value.

src/util/storage_file.c

@@ -27,7 +27,6 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include "dirname.h"
-#include "ignore-value.h"
 #include "memory.h"
 #include "virterror_internal.h"
 
@@ -253,7 +252,7 @@ absolutePathFromBaseFile(const char *base_file, const char *path)
     if (d_len > INT_MAX)
         return NULL;
 
-    ignore_value(virAsprintf(&res, "%.*s/%s", (int) d_len, base_file, path));
+    virAsprintf(&res, "%.*s/%s", (int) d_len, base_file, path);
     return res;
 }
 

src/util/util.h

@@ -177,8 +177,7 @@ int virMacAddrCompare (const char *mac1, const char *mac2);
 
 void virSkipSpaces(const char **str);
 int virParseNumber(const char **str);
-int virAsprintf(char **strp, const char *fmt, ...)
-    ATTRIBUTE_FMT_PRINTF(2, 3) ATTRIBUTE_RETURN_CHECK;
+int virAsprintf(char **strp, const char *fmt, ...) ATTRIBUTE_FMT_PRINTF(2, 3);
 char *virStrncpy(char *dest, const char *src, size_t n, size_t destbytes)
     ATTRIBUTE_RETURN_CHECK;
 char *virStrcpy(char *dest, const char *src, size_t destbytes)