lint: fix shell lint errors

ops/sqlite_lint_test.sh

@@ -9,17 +9,17 @@ set -e
 set -x
 
 PS4='+(${BASH_SOURCE}:${LINENO}): '
-cd "$(dirname ${BASH_SOURCE[0]})/.."
+cd "$(dirname "${BASH_SOURCE[0]}")/.."
 
 # Compile `gas`
-program="/tmp/gas"
-go build -o $program ./cmd
+gas="/tmp/gas"
+go build -o $gas ./cmd
 
 test_schema_dir="pkg/schema/lint/test_schemas"
 
 # Check all failure cases
-for test_schema in $test_schema_dir/failure-*; do
-    output=$($program sqlite_lint $test_schema) && {
+for test_schema in "$test_schema_dir"/failure-*; do
+    output=$($gas sqlite_lint "$test_schema") && {
         echo "Expected test to fail"
         exit 9
     }
@@ -33,7 +33,7 @@ done
 
 # Check success case
 success_schema="$test_schema_dir/success.sql"
-output=$($program sqlite_lint $success_schema) || {
+output=$($gas sqlite_lint $success_schema) || {
     echo "Expected test to succeed"
     exit 9
 }