Merge branch 'bugfix/vfs_fat_sdmmc_mount' into 'master'

Fix memory leak upon failure of esp_vfs_fat_sdmmc_mount()

Closes IDFGH-1969

See merge request espressif/esp-idf!6282

components/fatfs/vfs/vfs_fat_sdmmc.c

@@ -159,6 +159,8 @@ fail:
     ff_diskio_unregister(pdrv);
     free(s_card);
     s_card = NULL;
+    free(s_base_path);
+    s_base_path = NULL;
     return err;
 }