Fix pread64 and pwrite64 syscall entries

Fix pread64 and pwrite64 syscall entries

Change syscall names to match kernel __NR_* constants.

* linux/alpha/syscallent.h [349]: Rename "pread" to "pread64".
[350]: Rename "pwrite" to "pwrite64".
* linux/ia64/syscallent.h [1148]: Rename "pread" to "pread64".
[1149]: Rename "pwrite" to "pwrite64".
* linux/sh/syscallent.h [180]: Rename "pread" to "pread64".
[181]: Rename "pwrite" to "pwrite64".
* linux/sh64/syscallent.h: Likewise.
* linux/x32/syscallent.h [17]: Rename "pread" to "pread64".
[18]: Rename "pwrite" to "pwrite64".
* linux/x86_64/syscallent.h: Likewise.