Improve personality initialization

1. Personality parameter should be unsigned int (not long)
2. Do not reset bits outside of PER_MASK when setting
   personality value.
3. Set personality for static executables.

Bug: http://b/21900686
Change-Id: I4c7e34079cbd59b818ce221eed325c05b9bb2303
(cherry picked from commit f643eb38c36eb63f612e20dea09fd43ac6a6b360)
diff --git a/tests/sys_personality_test.cpp b/tests/sys_personality_test.cpp
index 55a023d..2dfaa65 100644
--- a/tests/sys_personality_test.cpp
+++ b/tests/sys_personality_test.cpp
@@ -19,7 +19,7 @@
 #include <sys/personality.h>
 
 TEST(sys_personality, current_persona) {
-  int persona = personality(0xffffffff);
+  int persona = personality(0xffffffff) & PER_MASK;
 #if defined(__BIONIC__)
 #if defined(__LP64__)
   ASSERT_EQ(PER_LINUX, persona);