nios2: Correct guard #defines in bits/kernel_types.h

The guards in posix_types.h are called _ASM_NIOS2_POSIX_TYPES_H, so
correctly use them here. Otherwise we wont be able to build uClibc
with headers exported from the current nios2 kernel.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

libc/sysdeps/linux/nios2/bits/kernel_types.h

@@ -4,8 +4,8 @@
  * our private content, and not the kernel header, will win.
  *  -Erik
  */
-#ifndef __ARCH_NIOS2_POSIX_TYPES_H
-#define __ARCH_NIOS2_POSIX_TYPES_H
+#ifndef _ASM_NIOS2_POSIX_TYPES_H
+#define _ASM_NIOS2_POSIX_TYPES_H
 
 typedef unsigned long	__kernel_dev_t;
 typedef unsigned long	__kernel_ino_t;
@@ -41,4 +41,4 @@ typedef struct {
 #endif
 } __kernel_fsid_t;
 
-#endif /* __ARCH_NIOS2_POSIX_TYPES_H */
+#endif /* _ASM_NIOS2_POSIX_TYPES_H */