selftests/kcmp: Make the test output consistent and clear

Make the output format of this test consistent. Currently the output is
as follows:

+TAP version 13
+1..1
+# selftests: kcmp: kcmp_test
+# pid1:  45814 pid2:  45815 FD:  1 FILES:  1 VM:  2 FS:  1 SIGHAND:  2
+  IO:  0 SYSVSEM:  0 INV: -1
+# PASS: 0 returned as expected
+# PASS: 0 returned as expected
+# PASS: 0 returned as expected
+# # Planned tests != run tests (0 != 3)
+# # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0
+# # Planned tests != run tests (0 != 3)
+# # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0
+# # Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0
+ok 1 selftests: kcmp: kcmp_test

With this patch applied the output is as follows:

+TAP version 13
+1..1
+# selftests: kcmp: kcmp_test
+# TAP version 13
+# 1..3
+# pid1:  46330 pid2:  46331 FD:  1 FILES:  2 VM:  2 FS:  2 SIGHAND:  1
+  IO:  0 SYSVSEM:  0 INV: -1
+# PASS: 0 returned as expected
+# PASS: 0 returned as expected
+# PASS: 0 returned as expected
+# # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0
+ok 1 selftests: kcmp: kcmp_test

Signed-off-by: Gautam Menghani <gautammenghani201@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>