[SCSI] fcoe, libfc: use single frame allocation API

Cleans up frame allocation APIs to have just single fc_frame_alloc API.

Removes _fc_frame_alloc, renames __fc_frame_alloc to _fc_frame_alloc.

Modifies fc_fcp_send_data for removed _fc_frame_alloc, fc_fcp_send_data
was the only user of removed _fc_frame_alloc.

Also Adds check in fc_frame_alloc to do mod by 4 for only non-zero
len value.

This patch is prep work to fix can_queue reducing in next patch.
Single fc_frame_alloc API helps in fixing can_queue reducing in
next patch.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/include/scsi/fc_frame.h b/include/scsi/fc_frame.h
index ab2f8d4..4d3e9c7 100644
--- a/include/scsi/fc_frame.h
+++ b/include/scsi/fc_frame.h
@@ -100,17 +100,7 @@
 }
 
 struct fc_frame *fc_frame_alloc_fill(struct fc_lport *, size_t payload_len);
-
-struct fc_frame *__fc_frame_alloc(size_t payload_len);
-
-/*
- * Get frame for sending via port.
- */
-static inline struct fc_frame *_fc_frame_alloc(struct fc_lport *dev,
-					       size_t payload_len)
-{
-	return __fc_frame_alloc(payload_len);
-}
+struct fc_frame *_fc_frame_alloc(size_t payload_len);
 
 /*
  * Allocate fc_frame structure and buffer.  Set the initial length to
@@ -124,10 +114,10 @@
 	 * Note: Since len will often be a constant multiple of 4,
 	 * this check will usually be evaluated and eliminated at compile time.
 	 */
-	if ((len % 4) != 0)
+	if (len && len % 4)
 		fp = fc_frame_alloc_fill(dev, len);
 	else
-		fp = _fc_frame_alloc(dev, len);
+		fp = _fc_frame_alloc(len);
 	return fp;
 }