Remove __INTRODUCED_IN from a typedef

__INTRODUCED_IN only applies to function or variable declarations, not
a typedef to a function pointer.

Bug: https://github.com/android-ndk/ndk/issues/706
Bug: http://b/113052379
Test: builds
Change-Id: I472565d3e34e5c6a3cd88500ad03ef9ce4489c25
Merged-In: I472565d3e34e5c6a3cd88500ad03ef9ce4489c25
(cherry picked from commit e0ec2e3fb2da0d7617f58e0cdbbbb83a75a8d1f0)
1 file changed