[DebugInfo] Eliminate compilation warning about used variable LSDA

The waring was:
lib/DebugInfo/DWARF/DWARFDebugFrame.cpp:643:20: warning: variable ‘LSDA’ set but not used

llvm-svn: 259877
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
index 3f8ed43..6d59a8e 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
@@ -640,9 +640,8 @@
             Offset + static_cast<uint32_t>(AugmentationLength);
 
           // Decode the LSDA if the CIE augmentation string said we should.
-          uint64_t LSDA = 0;
           if (Cie->getLSDAPointerEncoding() != DW_EH_PE_omit)
-            LSDA = readPointer(Data, Offset, Cie->getLSDAPointerEncoding());
+            readPointer(Data, Offset, Cie->getLSDAPointerEncoding());
 
           if (Offset != EndAugmentationOffset)
             ReportError("Parsing augmentation data at %lx failed");