perf record: Fix bug mismatch with -c option definition

perf record: Fix bug mismatch with -c option definition

The -c option defines the user requested sampling period. It was implemented
using an unsigned int variable but the type of the option was OPT_LONG. Thus,
the option parser was overwriting memory belonging to other variables, namely
the mmap_pages leading to a zero page sampling buffer. The bug was exposed only
when compiling at -O0, probably because the compiler was padding variables at
higher optimization levels.

This patch fixes this problem by declaring user_interval as u64. This also
avoids wrap-around issues for large period on 32-bit systems.

Commiter note:

Made it use OPT_U64(user_interval) after implementing OPT_U64 in the
previous patch.

Cc: David S. Miller <[email protected]>
Cc: Frédéric Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
LKML-Reference: <4bf11ae9.e88cd80a.06b0.ffffa8e3@mx.google.com>
Signed-off-by: Stephane Eranian <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>