Fix 32-bit MAXOFFSET_T definition

The correct definition of MAXOFFSET_T under Solaris is in reality
tied to the maximum size of a 'long long' type.  With this in mind
MAXOFFSET_T is now defined as LLONG_MAX which ensures the correct
value is used on both 32-bit and 64-bit systems.

include/sys/sysmacros.h

@@ -65,13 +65,7 @@
 #define MAXMSGLEN			256
 #define MAXNAMELEN			256
 #define MAXPATHLEN			PATH_MAX
-
-#ifdef _LP64
-#define MAXOFFSET_T			0x7fffffffffffffffl
-#else
-#define MAXOFFSET_T			0x7fffffffl
-#endif
-
+#define MAXOFFSET_T			LLONG_MAX
 #define MAXBSIZE			8192
 #define DEV_BSIZE			512
 #define DEV_BSHIFT			9 /* log2(DEV_BSIZE) */