common: env_sf: Add exclamation mark

Add exclamation mark to the errmsg, when error and set_default_env.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Mario Schuknecht <mario.schuknecht@dresearch-fe.de>
Cc: Vignesh R <vigneshr@ti.com>
Cc: Jagan Teki <jteki@openedev.com>
Cc: Ravi Babu <ravibabu@ti.com>
Cc: York Sun <york.sun@nxp.com>
Cc: Tom Rini <trini@konsulko.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/common/env_sf.c b/common/env_sf.c
index 892e6cb..273098c 100644
--- a/common/env_sf.c
+++ b/common/env_sf.c
@@ -225,7 +225,7 @@
 	ret = env_import((char *)ep, 0);
 	if (!ret) {
 		error("Cannot import environment: errno = %d\n", errno);
-		set_default_env("env_import failed");
+		set_default_env("!env_import failed");
 	}
 
 err_read: