.ci-coverity-scan-build.sh: Fix two shellcheck notes

The notes were:
Double quote to prevent globbing and word splitting. [SC2086]

[skip ci]

Author: fxlb

.ci-coverity-scan-build.sh

@@ -46,7 +46,7 @@ if [ ! -d $TOOL_BASE ]; then
 fi
 
 TOOL_DIR=$(find $TOOL_BASE -type d -name 'cov-analysis*')
-export PATH=$TOOL_DIR/bin:$PATH
+export PATH="$TOOL_DIR/bin:$PATH"
 
 # Build
 printf "\033[33;1mRunning Coverity Scan Analysis Tool...\033[0m\n"