perf hists browser: Fixup the "cpu" column width calculation
perf hists browser: Fixup the "cpu" column width calculation

Since we were not setting it to at least 3 chars ('CPU'), it was being
reset to zero when recalculating the columns width when refreshing the
screen, in 'perf top'. Fix it.

Tested-by: Wang Nan <7b589a40e0ecd4816b422e8ed1f74a01c34bf6bb@huawei.com>
Cc: Adrian Hunter <41bb5944f244750b7cf0394140496972a3f1bee3@intel.com>
Cc: Borislav Petkov <0691a664b24b6f15b20cd5aee64b72271db08be1@suse.de>
Cc: David Ahern <b80c1600f604d3b0d768f26f90a76757e76005dd@gmail.com>
Cc: Frederic Weisbecker <e8a1bf9163cb25e93cfd6540f223b3872ea7ee55@gmail.com>
Cc: Jiri Olsa <2c6594f608aa3d41e98d48846a6328831f7084ad@redhat.com>
Cc: Kan Liang <6e4ed0645dbf05e706dc43d69b381839dca8944b@intel.com>
Cc: Namhyung Kim <5c915a589b3ddf58cebf14bec41bcc143b37ac3c@kernel.org>
Cc: Stephane Eranian <f199ae9781930a5b94b284ca2f471140752002a7@google.com>
Link: 496ec8b1ff0dbe115590724a4f8aec1cf854cfff@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <293abb6b76d7791c0732cc517d38c4b5c734b87f@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs