Switch to the upstream OpenBSD getenv/putenv/setenv implementation.

This fixes all the bugs found by the new tests.

Change-Id: Id5a5f9f39a0620208bafa053f871a044725b4795
diff --git a/libc/Android.mk b/libc/Android.mk
index e183fb0..b674adf 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -39,7 +39,6 @@
 libc_common_src_files := \
     bionic/arc4random.c \
     bionic/bindresvport.c \
-    bionic/clearenv.c \
     bionic/daemon.c \
     bionic/err.c \
     bionic/ether_aton.c \
@@ -77,9 +76,6 @@
     stdio/snprintf.c\
     stdio/sprintf.c \
     stdlib/atexit.c \
-    stdlib/getenv.c \
-    stdlib/putenv.c \
-    stdlib/setenv.c \
     unistd/syslog.c \
 
 # Fortify implementations of libc functions.
@@ -112,6 +108,7 @@
     bionic/brk.cpp \
     bionic/chmod.cpp \
     bionic/chown.cpp \
+    bionic/clearenv.cpp \
     bionic/clock.cpp \
     bionic/clone.cpp \
     bionic/cmsg_nxthdr.cpp \
@@ -404,6 +401,8 @@
     upstream-openbsd/lib/libc/stdlib/atoi.c \
     upstream-openbsd/lib/libc/stdlib/atol.c \
     upstream-openbsd/lib/libc/stdlib/atoll.c \
+    upstream-openbsd/lib/libc/stdlib/getenv.c \
+    upstream-openbsd/lib/libc/stdlib/setenv.c \
     upstream-openbsd/lib/libc/stdlib/strtoimax.c \
     upstream-openbsd/lib/libc/stdlib/strtol.c \
     upstream-openbsd/lib/libc/stdlib/strtoll.c \