common: Move flash_perror() to flash.h

This function belongs more in flash.h than common.h so move it.

Also remove the space before the bracket in some calls.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/net/nfs.c b/net/nfs.c
index 97e62f1..f4101eb 100644
--- a/net/nfs.c
+++ b/net/nfs.c
@@ -28,6 +28,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <flash.h>
 #include <net.h>
 #include <malloc.h>
 #include <mapmem.h>