Prevent the madvise(MADV_MERGEABLE) mmap hack from affecting errno.

Bug: 9889616
Change-Id: I4a7323e0ae5aeb5cbe0da1b2bc7501d83b3a2aa4
diff --git a/libc/Android.mk b/libc/Android.mk
index 0e93acd..38678f5 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -106,7 +106,6 @@
 	bionic/md5.c \
 	bionic/memmem.c \
 	bionic/memswap.c \
-	bionic/mmap.c \
 	bionic/openat.c \
 	bionic/open.c \
 	bionic/pathconf.c \
@@ -200,6 +199,7 @@
     bionic/__memcpy_chk.cpp \
     bionic/__memmove_chk.cpp \
     bionic/__memset_chk.cpp \
+    bionic/mmap.cpp \
     bionic/pthread_attr.cpp \
     bionic/pthread_detach.cpp \
     bionic/pthread_equal.cpp \