scsi: bfa: Replace one-element array with flexible-array member in struct fc_rscn_pl_s

One-element and zero-length arrays are deprecated. So, replace one-element
array in struct fc_rscn_pl_s with flexible-array member.

This results in no differences in binary output.

Link: KSPP/linux#339
Signed-off-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/ZN0VTpDBOSVHGayb@work
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: GustavoARSilva

drivers/scsi/bfa/bfa_fc.h

@@ -800,7 +800,7 @@ struct fc_rscn_pl_s {
 	u8	command;
 	u8	pagelen;
 	__be16	payldlen;
-	struct fc_rscn_event_s event[1];
+	struct fc_rscn_event_s event[];
 };
 
 /*

drivers/scsi/bfa/bfa_fcbuild.c

@@ -1051,7 +1051,7 @@ fc_rscn_build(struct fchs_s *fchs, struct fc_rscn_pl_s *rscn,
 	rscn->event[0].format = FC_RSCN_FORMAT_PORTID;
 	rscn->event[0].portid = s_id;
 
-	return sizeof(struct fc_rscn_pl_s);
+	return struct_size(rscn, event, 1);
 }
 
 u16