libertas: Check return status of command functions

Return status of lbs_prepare_and_send_command and lbs_cmd_with_response
functions is not checked at some places. Those checks are added.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/libertas/debugfs.c b/drivers/net/wireless/libertas/debugfs.c
index 893a55c..587b0cb 100644
--- a/drivers/net/wireless/libertas/debugfs.c
+++ b/drivers/net/wireless/libertas/debugfs.c
@@ -451,10 +451,12 @@
 				CMD_MAC_REG_ACCESS, 0,
 				CMD_OPTION_WAITFORRSP, 0, &offval);
 	mdelay(10);
-	pos += snprintf(buf+pos, len-pos, "MAC[0x%x] = 0x%08x\n",
+	if (!ret) {
+		pos += snprintf(buf+pos, len-pos, "MAC[0x%x] = 0x%08x\n",
 				priv->mac_offset, priv->offsetvalue.value);
 
-	ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
+		ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
+	}
 	free_page(addr);
 	return ret;
 }
@@ -514,7 +516,8 @@
 				CMD_OPTION_WAITFORRSP, 0, &offval);
 	mdelay(10);
 
-	res = count;
+	if (!res)
+		res = count;
 out_unlock:
 	free_page(addr);
 	return res;
@@ -539,10 +542,12 @@
 				CMD_BBP_REG_ACCESS, 0,
 				CMD_OPTION_WAITFORRSP, 0, &offval);
 	mdelay(10);
-	pos += snprintf(buf+pos, len-pos, "BBP[0x%x] = 0x%08x\n",
+	if (!ret) {
+		pos += snprintf(buf+pos, len-pos, "BBP[0x%x] = 0x%08x\n",
 				priv->bbp_offset, priv->offsetvalue.value);
 
-	ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
+		ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
+	}
 	free_page(addr);
 
 	return ret;
@@ -603,7 +608,8 @@
 				CMD_OPTION_WAITFORRSP, 0, &offval);
 	mdelay(10);
 
-	res = count;
+	if (!res)
+		res = count;
 out_unlock:
 	free_page(addr);
 	return res;
@@ -628,10 +634,12 @@
 				CMD_RF_REG_ACCESS, 0,
 				CMD_OPTION_WAITFORRSP, 0, &offval);
 	mdelay(10);
-	pos += snprintf(buf+pos, len-pos, "RF[0x%x] = 0x%08x\n",
+	if (!ret) {
+		pos += snprintf(buf+pos, len-pos, "RF[0x%x] = 0x%08x\n",
 				priv->rf_offset, priv->offsetvalue.value);
 
-	ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
+		ret = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
+	}
 	free_page(addr);
 
 	return ret;
@@ -692,7 +700,8 @@
 				CMD_OPTION_WAITFORRSP, 0, &offval);
 	mdelay(10);
 
-	res = count;
+	if (!res)
+		res = count;
 out_unlock:
 	free_page(addr);
 	return res;