Fix code warning.

Change-Id: Ib11fb49f528d3688351ae349d5b4e307c28b3967
diff --git a/mbtk/libmbtk_lib/gnss/mbtk_gnss.c b/mbtk/libmbtk_lib/gnss/mbtk_gnss.c
index cf9af27..707b9de 100755
--- a/mbtk/libmbtk_lib/gnss/mbtk_gnss.c
+++ b/mbtk/libmbtk_lib/gnss/mbtk_gnss.c
@@ -46,7 +46,7 @@
 extern long timezone;
 #endif
 
-static int sock_read(int fd, uint8 *msg, int data_len)
+static int sock_read(int fd, void *msg, int data_len)
 {
     memset(msg, 0, data_len);
     int len = 0;
@@ -89,7 +89,7 @@
     }
 }
 
-static int sock_write(int fd, uint8 *msg, int data_len)
+static int sock_write(int fd, void *msg, int data_len)
 {
     int len = 0;
     int write_len = 0;
@@ -161,6 +161,7 @@
     return 0;
 }
 
+#if 0
 static int str2int( const char* head, const char* end )
 {
     int result = 0;
@@ -185,6 +186,7 @@
 Fail:
     return -1;
 }
+#endif
 
 static double str2float( const char* head, const char* end )
 {
@@ -366,7 +368,6 @@
 
 static int nmea_update_latlong(mbtk_gnss_location_info_t* locl_info, mbtk_token         latitude, mbtk_token longitude)
 {
-    double   lat, lon;
     mbtk_token    tok;
     tok = latitude;
     if (tok.head + 6 > tok.end)
@@ -517,7 +518,7 @@
 #if MBTK_GNSS_LOG_ENABLED
                     LOGD("gnss_cb: [%p], locl_info.flags [%d]", gnss_cb, locl_info.flags);
 #endif
-                    if(locl_info.flags == GNSS_LOCATION_HAS_ALL) {
+                    if(ret == 0 && locl_info.flags == GNSS_LOCATION_HAS_ALL) {
                         gnss_cb(MBTK_GNSS_IND_LOCATION, &locl_info, sizeof(mbtk_gnss_location_info_t));
                         locl_info.flags = 0;
                     }
@@ -712,7 +713,9 @@
     }
 
     if(exit_fd[1] > 0) {
-        write(exit_fd[1], "EXIT", 4);
+        if(4 != write(exit_fd[1], "EXIT", 4)) {
+            LOGE("write EXIT fail.");
+        }
     }
 
     int ret = pthread_join(read_thread_id, NULL);