[PATCH] isci: avoid array subscript warning

[Arnd Bergmann]

I'm getting a new warning with gcc-7:

isci/remote_node_context.c: In function 'sci_remote_node_context_destruct':
isci/remote_node_context.c:69:16: error: array subscript is above array bounds [-Werror=array-bounds]

This is odd, since we clearly cover all values for enum
scis_sds_remote_node_context_states here. Anyway, checking
for an array overflow can't harm and it makes the warning
go away.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 drivers/scsi/isci/remote_node_context.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/isci/remote_node_context.c b/drivers/scsi/isci/remote_node_context.c
index 30bd80052e03..e3f2a5359d71 100644
--- a/drivers/scsi/isci/remote_node_context.c
+++ b/drivers/scsi/isci/remote_node_context.c
@@ -66,6 +66,9 @@ const char *rnc_state_name(enum scis_sds_remote_node_context_states state)
 {
 	static const char * const strings[] = RNC_STATES;
 
+	if (state >= ARRAY_SIZE(strings))
+		return "UNKNOWN";
+
 	return strings[state];
 }
 #undef C
-- 
2.9.0