Fix build warning

When enabling build warnings as errors, this is causing the build to
fail as an invalid conversion, so add a static_cast to avoid the
warning.

Tested:
Confirmed that CI passes

Change-Id: I37f9ca0e6bdbeadcfb5a804a36cac57efe296a6d
Signed-off-by: Jason M. Bills <jason.m.bills@intel.com>
diff --git a/dbus_raw_peci.cpp b/dbus_raw_peci.cpp
index adb0013..1016a45 100644
--- a/dbus_raw_peci.cpp
+++ b/dbus_raw_peci.cpp
@@ -70,7 +70,8 @@
                 }
                 rawResp[i].resize(rawCmd[2]);
                 peci_raw(rawCmd[0], rawCmd[2], &rawCmd[3], rawCmd[1],
-                         rawResp[i].data(), rawResp[i].size());
+                         rawResp[i].data(),
+                         static_cast<uint32_t>(rawResp[i].size()));
             }
             peci_SetDevName(NULL);
             return rawResp;