simpleperf: add kmem command to report slab allocation information.

Bug: 27403614

Change-Id: Id3015a4828ec32170ea1db3a1580b14a8bd159ba
diff --git a/simpleperf/dso.cpp b/simpleperf/dso.cpp
index 4453817..45ae124 100644
--- a/simpleperf/dso.cpp
+++ b/simpleperf/dso.cpp
@@ -262,8 +262,7 @@
     if (all_zero) {
       LOG(WARNING)
           << "Symbol addresses in /proc/kallsyms on device are all zero. "
-             "`echo 0 >/proc/sys/kernel/kptr_restrict` or use root privilege "
-             "if possible.";
+             "`echo 0 >/proc/sys/kernel/kptr_restrict` if possible.";
       symbols_.clear();
       return false;
     }
@@ -296,8 +295,7 @@
     }
     if (all_zero) {
       LOG(WARNING) << "Symbol addresses in /proc/kallsyms are all zero. "
-                      "`echo 0 >/proc/sys/kernel/kptr_restrict` or use root "
-                      "privilege if possible.";
+                      "`echo 0 >/proc/sys/kernel/kptr_restrict` if possible.";
       symbols_.clear();
       return false;
     }