Less verbose output when loading vxworks 6.x images

Loading vxWorks 5.x images resulted just into 3 or 4 lines of output.
With vxWorks 6.x and the new GCC it emits about 30 lines, which is
far too noisy in my opinion.

Signed-off-by: Niklaus Giger <niklaus.giger@member.fsf.org>
diff --git a/common/cmd_elf.c b/common/cmd_elf.c
index abec7dd..63f6fe7 100644
--- a/common/cmd_elf.c
+++ b/common/cmd_elf.c
@@ -287,7 +287,7 @@
 		}
 
 		if (strtab) {
-			printf ("%sing %s @ 0x%08lx (%ld bytes)\n",
+			debug("%sing %s @ 0x%08lx (%ld bytes)\n",
 				(shdr->sh_type == SHT_NOBITS) ?
 					"Clear" : "Load",
 				&strtab[shdr->sh_name],