Fix leaks in wifi_chip.cpp.

Use closedir on DIR*, instead of close(dirfd(DIR*)).

Bug: http://b/109702699
Test: mma
Change-Id: I827d3a414761bb836d5360221296823fcb34cd6b
Merged-In: I827d3a414761bb836d5360221296823fcb34cd6b
1 file changed