Linux 5.19 compat: zap_flags_t conflict

As of the Linux 5.19 kernel an identically named zap_flags_t typedef
is declared in the include/linux/mm_types.h linux header.  Sadly,
the inclusion of this header cannot be easily avoided.  To resolve
the conflict a #define is used to remap the name in the OpenZFS
sources when building against the Linux kernel.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #13515

include/sys/zap.h

@@ -110,7 +110,12 @@ typedef enum zap_flags {
 	 * already randomly distributed.
 	 */
 	ZAP_FLAG_PRE_HASHED_KEY = 1 << 2,
+#if defined(__linux__) && defined(_KERNEL)
+} zfs_zap_flags_t;
+#define	zap_flags_t	zfs_zap_flags_t
+#else
 } zap_flags_t;
+#endif
 
 /*
  * Create a new zapobj with no attributes and return its object number.