ld: optimize vfinfo output slightly

ld atm ends up calling the write() syscall on every char when displaying
an error message.  For example:
$ echo 'main(){foo();}' | strace -f -ewrite gcc -x c -o /dev/null -
...
[pid 13035] write(2, ":", 1)            = 1
[pid 13035] write(2, " ", 1)            = 1
[pid 13035] write(2, "I", 1)            = 1
[pid 13035] write(2, "n", 1)            = 1
[pid 13035] write(2, " ", 1)            = 1
[pid 13035] write(2, "f", 1)            = 1
[pid 13035] write(2, "u", 1)            = 1
[pid 13035] write(2, "n", 1)            = 1
[pid 13035] write(2, "c", 1)            = 1
[pid 13035] write(2, "t", 1)            = 1
[pid 13035] write(2, "i", 1)            = 1
[pid 13035] write(2, "o", 1)            = 1
[pid 13035] write(2, "n", 1)            = 1
[pid 13035] write(2, " ", 1)            = 1
[pid 13035] write(2, "`", 1)            = 1
...

That's just to write ": In function `main':".  A slight optimization in
the vfinfo() func gives a much more reasonable syscall footprint:
...
write(2, ": In function `", 15)         = 15
...

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

ld/ChangeLog

@@ -1,3 +1,9 @@
+2012-04-02  Mike Frysinger  <vapier@gentoo.org>
+
+	* ldmisc.c (vfinfo): Assign new local str to fmt.  Delete
+	putc call.  If str and fmt are different, call fwrite on
+	the difference.
+
 2012-03-30  Nick Clifton  <nickc@redhat.com>
 
 	* po/vi.po: Updated Vietnamese translation.

ld/ldmisc.c

@@ -72,10 +72,13 @@ vfinfo (FILE *fp, const char *fmt, va_list arg, bfd_boolean is_warning)
 
   while (*fmt != '\0')
     {
+      const char *str = fmt;
       while (*fmt != '%' && *fmt != '\0')
-	{
-	  putc (*fmt, fp);
 	fmt++;
+      if (fmt != str)
+	if (fwrite (str, 1, fmt - str, fp))
+	  {
+	    /* Ignore.  */
 	  }
 
       if (*fmt == '%')