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

linker/linker.cpp

@@ -37,7 +37,6 @@
 #include <string.h>
 #include <sys/mman.h>
 #include <sys/param.h>
-#include <sys/personality.h>
 #include <unistd.h>
 
 #include <new>
@@ -3111,12 +3110,6 @@ static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW(
     ldpreload_env = getenv("LD_PRELOAD");
   }
 
-#if !defined(__LP64__)
-  if (personality(PER_LINUX32) == -1) {
-    __libc_fatal("error setting PER_LINUX32 personality: %s", strerror(errno));
-  }
-#endif
-
   INFO("[ android linker & debugger ]");
 
   soinfo* si = soinfo_alloc(args.argv[0], nullptr, 0, RTLD_GLOBAL);