fix: correct calculating system shared memory size

do not exceed system memory region size when region is available

Related-To: HSD-18038050680
Signed-off-by: Mateusz Jablonski <mateusz.jablonski@intel.com>

shared/source/os_interface/linux/sys_calls_linux.cpp

@@ -193,5 +193,8 @@ int closedir(DIR *dir) {
 off_t lseek(int fd, off_t offset, int whence) noexcept {
     return ::lseek(fd, offset, whence);
 }
+long sysconf(int name) {
+    return ::sysconf(name);
+}
 } // namespace SysCalls
 } // namespace NEO