sparc: Fix compiler warning (fprintf format string)

When argument checking is enabled, gcc throws this error:

error: format not a string literal and no format arguments

The patch rewrites the statement to satisfy the compiler.
Signed-off-by: NStefan Weil <weil@mail.berlios.de>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

sparc-dis.c

@@ -2778,7 +2778,7 @@ print_insn_sparc (bfd_vma memaddr, disassemble_info *info)
               /* Can't do simple format if source and dest are different.  */
               continue;
 
-          (*info->fprintf_func) (stream, opcode->name);
+          (*info->fprintf_func) (stream, "%s", opcode->name);
 
           {
             const char *s;