transceiver52M: bump critial errors to ALERT level

Device errors regarding properties such as sample
rate or frequency tuning are almost always fatal and
lead to the common error "assuming TRX is dead".
Make sure that these errors are clearly presented to
the user.

Signed-off-by: Thomas Tsou <ttsou@vt.edu>

git-svn-id: http://wush.net/svn/range/software/public/openbts/trunk@2700 19bc5d8c-e614-43d4-8b26-e1612bc8e597
diff --git a/Transceiver52M/USRPDevice.cpp b/Transceiver52M/USRPDevice.cpp
index 175b187..e321b0a 100644
--- a/Transceiver52M/USRPDevice.cpp
+++ b/Transceiver52M/USRPDevice.cpp
@@ -522,7 +522,7 @@
     return true;
   }
   else {
-    LOG(ERR) << "set TX: " << wFreq << "failed" << std::endl
+    LOG(ALERT) << "set TX: " << wFreq << "failed" << std::endl
                << "    baseband freq: " << result.baseband_freq << std::endl
                << "    DDC freq:      " << result.dxc_freq << std::endl
                << "    residual freq: " << result.residual_freq;
@@ -542,7 +542,7 @@
     return true;
   }
   else {
-    LOG(ERR) << "set RX: " << wFreq << "failed" << std::endl
+    LOG(ALERT) << "set RX: " << wFreq << "failed" << std::endl
                << "    baseband freq: " << result.baseband_freq << std::endl
                << "    DDC freq:      " << result.dxc_freq << std::endl
                << "    residual freq: " << result.residual_freq;