sysconf(3) returns long.

On LP32, this makes no difference. Not an ABI change.

On LP64, results are going to be in %rax or x0 whether they're 32- or 64-bit,
and the only difference is going to be whether the top bits are clobbered.

(cherry picked from commit 60d84af172)

Bug: 18390956
Change-Id: I722461498bc5494e2972fb07d5189dffe76e8993

libc/bionic/sysconf.cpp

@@ -150,7 +150,7 @@ static int __sysconf_monotonic_clock() {
   return (rc == -1) ? -1 : _POSIX_VERSION;
 }
 
-int sysconf(int name) {
+long sysconf(int name) {
     switch (name) {
 #ifdef _POSIX_ARG_MAX
     case _SC_ARG_MAX:           return _POSIX_ARG_MAX;

libc/include/sys/sysconf.h

@@ -129,7 +129,7 @@ __BEGIN_DECLS
 #define _SC_AVPHYS_PAGES                0x0063
 #define _SC_MONOTONIC_CLOCK             0x0064
 
-extern int sysconf(int name);
+long sysconf(int);
 
 __END_DECLS
 

libc/include/unistd.h

@@ -177,7 +177,7 @@ extern int  acct(const char*  filepath);
 
 int getpagesize(void);
 
-extern int sysconf(int  name);
+long sysconf(int);
 
 extern int daemon(int, int);