scsi: fnic: Remove unnecessary cast

Fix the following coccicheck warning:
WARNING: casting value returned by memory allocation function is useless.

Link: https://lore.kernel.org/r/1615515500-946-1-git-send-email-wangqing@vivo.com
Signed-off-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/fnic/fnic_debugfs.c

@@ -58,8 +58,7 @@ int fnic_debugfs_init(void)
 						fnic_trace_debugfs_root);
 
 	/* Allocate memory to structure */
-	fc_trc_flag = (struct fc_trace_flag_type *)
-		vmalloc(sizeof(struct fc_trace_flag_type));
+	fc_trc_flag = vmalloc(sizeof(struct fc_trace_flag_type));
 
 	if (fc_trc_flag) {
 		fc_trc_flag->fc_row_file = 0;