Android: Fix QString(char*) warnings in qlogging.cpp

Both context.file and context.function are already char*, so
using qPrintable() here would first convert them to QString()
with the scary constructor and then back again.

Change-Id: I822655c37fb8b9baaddc8f95d7c1842519859a0e
Reviewed-by: Christian Stromme <christian.stromme@digia.com>
Fix unused static function randTLS() warning

Match the preprocessor conditions for using the randTLS() function
in the place where it's defined, otherwise we will get a warning
for this.

Change-Id: I0fa20f2671da618e31f30a4536f55bc680131e4d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Fix unsigned/signed comparison warning in qnativesocketengine_unix

This triggered when building on Android. Make sure we cast the
sizeof() to the same type as the variable we compare to.

Change-Id: I65d4fe7edc2a39f1a4b68e78f4c19bff6e4aa0f8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>