befs: make consistent use of befs_error()

befs_error() is used in potential errors that could happen in befs to
provide informational log messages. befs_debug() is silent when
CONFIG_BEFS_DEBUG=no, and very verbose when switched on, which is why it is
used for general debugging but not for errors.

Fix a few cases where the befs debug utility usage isn't following the
expected pattern. To make sure we have consistent information in the logs.

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index e0979a4..67669a8 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -187,7 +187,7 @@
 		return ERR_PTR(-ENOENT);
 
 	} else if (ret != BEFS_OK || offset == 0) {
-		befs_warning(sb, "<--- %s Error", __func__);
+		befs_error(sb, "<--- %s Error", __func__);
 		return ERR_PTR(-ENODATA);
 	}