microblaze: bootm: Fix compiler warning

Fix build warning in arch/microblaze/lib/bootm.c with gcc 7.3.0:

  warning: this 'if' clause does not guard... [-Wmisleading-indentation]

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/microblaze/lib/bootm.c b/arch/microblaze/lib/bootm.c
index 0a286e8..93525cc 100644
--- a/arch/microblaze/lib/bootm.c
+++ b/arch/microblaze/lib/bootm.c
@@ -62,11 +62,12 @@
 		of_flat_tree = (char *)simple_strtoul(argv[1], NULL, 16);
 
 	/* fixup the initrd now that we know where it should be */
-	if (images->rd_start && images->rd_end && of_flat_tree)
+	if (images->rd_start && images->rd_end && of_flat_tree) {
 		ret = fdt_initrd(of_flat_tree, images->rd_start,
 				 images->rd_end);
 		if (ret)
 			return 1;
+	}
 
 #ifdef DEBUG
 	printf("## Transferring control to Linux (at address 0x%08lx) ",