psusensor: fix psu pwm sensor name

Current bug is that psusensor service does not create pwm sensor object
if pid fan configuration has spaces in Name field, like
{
...
"Name" : "PSU$BUS $ADDRESS Fan 1"
"Outputs": [
	"Pwm PSU$BUS $ADDRESS Fan 1"
                ],
...
}

Fix:
Pwm name need to be escaped, which currently replaces " " with "_"
before being passed to CreatePwmSensor in PSUSensor service.
PwmSensor constructor takes the name as is.

Since the escape algorithm may change in the future,
add a helper function escapeName() and update dbus-sensors
to use this helper funtion when sensors are created.
escapeName() currently calls boost replace_all_copy(name," ", "_"),
so it does not introduce functional changes except the bug identified
above.

Tested:
No regression found for existing working sensors.
Sensors are created as before with the same sensor name.

Fix for non-working case works correctly now.
psu pwm sensor name with space are created correctly with the change.
busctl tree xyz.openbmc_project.PSUSensor
...
    |-/xyz/openbmc_project/control
    | `-/xyz/openbmc_project/control/fanpwm
    |   |-/xyz/openbmc_project/control/fanpwm/Pwm_PSU17_2_Fan_1
    |   |-/xyz/openbmc_project/control/fanpwm/Pwm_PSU17_2_Fan_2
...

Signed-off-by: Zhikui Ren <zhikui.ren@intel.com>
Change-Id: If3b60f93de324e59cc3d774285c23bf50a6f989c
diff --git a/src/PSUSensorMain.cpp b/src/PSUSensorMain.cpp
index fd151d9..779873e 100644
--- a/src/PSUSensorMain.cpp
+++ b/src/PSUSensorMain.cpp
@@ -425,8 +425,7 @@
         // on rescans, only update sensors we were signaled by
         if (!firstScan)
         {
-            std::string psuNameStr =
-                "/" + boost::replace_all_copy(*psuName, " ", "_");
+            std::string psuNameStr = "/" + escapeName(*psuName);
             auto it =
                 std::find_if(sensorsChanged->begin(), sensorsChanged->end(),
                              [psuNameStr](std::string& s) {
@@ -458,7 +457,8 @@
         do
         {
             // Individual string fields: Name, Name1, Name2, Name3, ...
-            psuNames.push_back(std::get<std::string>(findPSUName->second));
+            psuNames.push_back(
+                escapeName(std::get<std::string>(findPSUName->second)));
             findPSUName = baseConfig->second.find("Name" + std::to_string(i++));
         } while (findPSUName != baseConfig->second.end());