Close adb_usb.ini after reading it

Signed-off-by: Chris Dearman <chris@mips.com>
Change-Id: I7d3ee8cbd54af206dac89225c438e6c7322c571f
diff --git a/adb/usb_vendors.c b/adb/usb_vendors.c
index 1c09b84..3a8e8fd 100644
--- a/adb/usb_vendors.c
+++ b/adb/usb_vendors.c
@@ -235,6 +235,7 @@
                     break;
                 }
             }
+            fclose(f);
         }
     }
 }