Cleanup: replace strncpy with BLI_strncpy

Also replace strncpy+strcat with BLI_string_join

source/blender/blenlib/intern/system.c

@@ -154,12 +154,12 @@ void BLI_hostname_get(char *buffer, size_t bufsize)
   if (gethostname(buffer, bufsize - 1) < 0) {
     BLI_strncpy(buffer, "-unknown-", bufsize);
   }
-  /* When gethostname() truncates, it doesn't guarantee the trailing \0. */
+  /* When `gethostname()` truncates, it doesn't guarantee the trailing `\0`. */
   buffer[bufsize - 1] = '\0';
 #else
   DWORD bufsize_inout = bufsize;
   if (!GetComputerName(buffer, &bufsize_inout)) {
-    strncpy(buffer, "-unknown-", bufsize);
+    BLI_strncpy(buffer, "-unknown-", bufsize);
   }
 #endif
 }