Telemetry: Don't use the full path to rdmsr on Linux.

tools/telemetry/telemetry/core/platform/linux_platform_backend.py

Index: tools/telemetry/telemetry/core/platform/linux_platform_backend.py
diff --git a/tools/telemetry/telemetry/core/platform/linux_platform_backend.py b/tools/telemetry/telemetry/core/platform/linux_platform_backend.py
index bea862803c9ed720698ed20b3697ea12252e7b7b..4a24b147c99c7dc0a9892c925c2fe8598f667208 100644
--- a/tools/telemetry/telemetry/core/platform/linux_platform_backend.py
+++ b/tools/telemetry/telemetry/core/platform/linux_platform_backend.py
@@ -104,7 +104,7 @@ class LinuxPlatformBackend(
     return self._power_monitor.StopMonitoringPower()
 
   def ReadMsr(self, msr_number, start=0, length=64):
-    cmd = ['/usr/sbin/rdmsr', '-d', str(msr_number)]
+    cmd = ['rdmsr', '-d', str(msr_number)]
     (out, err) = subprocess.Popen(cmd,
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE).communicate()