Fix compiler warning in UML code.

Simply putting (void) in front of the function call does not fix
the warning in GCC. This is working as intended; see:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25509#c26

Bug: 21631098
Change-Id: I3aff39752242923dab8b837df2b9ea697316165e
Git-Commit: 4a7f7d46ef4e0ac44dfc86fd8eb69046e1bf43df
Git-repo: https://android.googlesource.com/kernel/msm


[jshriram@codeaurora.org: for compiling UML build]
Signed-off-by: Jeevan Shriram <jshriram@codeaurora.org>