misc: mic: scif: scif_api: Remove set but unused variable 'read_size'

'read_size' appears to have been assigned, but never used since the
SCIF messaging and node enumeration APIs were introduced in 2015.
Makes sense to simply remove it.

Fixes the following W=1 warning:

 drivers/misc/mic/scif/scif_api.c: In function ‘_scif_recv’:
 drivers/misc/mic/scif/scif_api.c:1000:6: warning: variable ‘read_size’ set but not used [-Wunused-but-set-variable]
 1000 | int read_size;
 | ^~~~~~~~~
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200701083118.45744-19-lee.jones@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mic/scif/scif_api.c

@@ -997,7 +997,6 @@ static int _scif_send(scif_epd_t epd, void *msg, int len, int flags)
 
 static int _scif_recv(scif_epd_t epd, void *msg, int len, int flags)
 {
-	int read_size;
 	struct scif_endpt *ep = (struct scif_endpt *)epd;
 	struct scifmsg notif_msg;
 	int curr_recv_len = 0, remaining_len = len, read_count;
@@ -1017,8 +1016,7 @@ static int _scif_recv(scif_epd_t epd, void *msg, int len, int flags)
 			 * important for the Non Blocking case.
 			 */
 			curr_recv_len = min(remaining_len, read_count);
-			read_size = scif_rb_get_next(&qp->inbound_q,
-						     msg, curr_recv_len);
+			scif_rb_get_next(&qp->inbound_q, msg, curr_recv_len);
 			if (ep->state == SCIFEP_CONNECTED) {
 				/*
 				 * Update the read pointer only if the endpoint