MAINTAINERS: remove ANDROID ION pattern

MAINTAINERS: remove ANDROID ION pattern

The file drivers/staging/android/uapi/ion_test.h was removed by commit
2120b4c715a6 ("staging: android: ion: Remove old platform support")

Remove the pattern.

Link: http://lkml.kernel.org/r/182debec22002c9a1de44e79a7441288942b205c.1517147485.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>