Small syscall/nd_syscall tapset and testsuite fixes and improvements.
* tapset/linux/syscalls.stp (syscall.bind): Make 'fd' variable an integer
instead of a long.
* tapset/linux/nd_syscalls2.stp (nd_syscall.readv): Make 'fd' and 'count'
variables integers instead of longs.
(nd_syscall.writev): Ditto.
* testsuite/systemtap.syscall/rename.c (main): Fix typo in expected test
output.
* testsuite/systemtap.syscall/bind.c: New testcase.