Bug 1334302 - use MOZ_FORMAT_PRINTF in nsCSSRenderingBorders.h; r=mattwoodrow

Add MOZ_FORMAT_PRINTF to the definitions of PrintAsFormatString in
nsCSSRenderingBorders.h.

MozReview-Commit-ID: 9ZcSgNIPPhM

--HG--
extra : rebase_source : e2c3f86ac58835c0bdaf442f45fee25db99e52a6

layout/painting/nsCSSRenderingBorders.h

@@ -354,7 +354,7 @@ static inline void PrintAsStringNewline(const char *s = nullptr) {
   fflush (stderr);
 }
 
-static inline void PrintAsFormatString(const char *fmt, ...) {
+static inline MOZ_FORMAT_PRINTF(1, 2) void PrintAsFormatString(const char *fmt, ...) {
   va_list vl;
   va_start(vl, fmt);
   vfprintf (stderr, fmt, vl);
@@ -368,7 +368,7 @@ static inline void PrintAsString(const mozilla::gfx::Rect& r) {}
 static inline void PrintAsString(const mozilla::gfx::Float f) {}
 static inline void PrintAsString(const char *s) {}
 static inline void PrintAsStringNewline(const char *s = nullptr) {}
-static inline void PrintAsFormatString(const char *fmt, ...) {}
+static inline MOZ_FORMAT_PRINTF(1, 2) void PrintAsFormatString(const char *fmt, ...) {}
 #endif
 
 } // namespace mozilla