lint: Fix ShellCheck lints in Zcash scripts

contrib/docker/entrypoint.sh

@@ -11,7 +11,7 @@ fi
 env | sort | grep ZCASHD || true
 export ZCASHD_CMD='zcashd -printtoconsole'
 
-if [[ ! -n ${ZCASHD_NETWORK} ]];then
+if [[ -z ${ZCASHD_NETWORK} ]];then
   export ZCASHD_NETWORK=mainnet
 fi
 

test/lint/lint-cargo-patches.sh

@@ -29,7 +29,9 @@ EXIT_CODE=0
 # Check that every patch has a matching replacement.
 for PATCH in $(tail -n+$CARGO_TOML_PATCH_START $CARGO_TOML | sed 's/.*git = "\([^"]*\)", rev = "\([^"]*\)".*/\1#\2/' | sort | uniq)
 do
+    # shellcheck disable=SC2001
     PATCH_GIT=$(echo $PATCH | sed 's/#.*//')
+    # shellcheck disable=SC2001
     PATCH_REV=$(echo $PATCH | sed 's/.*#//')
 
     # Canonicalize the git URL (matching how Cargo treats them, so we don't over-lint).

zcutil/afl/afl-build.sh

@@ -11,7 +11,7 @@ export AFL_LOG_DIR
 
 for d in src/fuzzing/*/ ; do
     fuzz_cases+="$(basename "$d"), "
-    fuzz_cases_choices=("${fuzz_cases_choices[@]}" $(basename "$d"))
+    fuzz_cases_choices=("${fuzz_cases_choices[@]}" "$(basename "$d")")
 done
 
 FUZZ_OPTIONS_STRING="Options are: ${fuzz_cases::-2}"

zcutil/afl/afl-get.sh

@@ -55,7 +55,7 @@ fi
 mkdir -p "$AFL_INSTALL_DIR"
 cd "$AFL_INSTALL_DIR"
 
-if [ ! -z "$(ls -A .)" ]; then
+if [ -n "$(ls -A .)" ]; then
     echo "$1 is not empty. This script will only attempt to build AFL in an empty directory."
     exit 1
 fi
@@ -63,8 +63,7 @@ fi
 # Get the AFL source
 rm -f afl-latest.tgz
 wget https://lcamtuf.coredump.cx/afl/releases/afl-latest.tgz
-sha256sum afl-latest.tgz | grep '43614b4b91c014d39ef086c5cc84ff5f068010c264c2c05bf199df60898ce045'
-if [ "$?" != "0" ]
+if ! sha256sum afl-latest.tgz | grep '43614b4b91c014d39ef086c5cc84ff5f068010c264c2c05bf199df60898ce045';
 then
     echo "Wrong SHA256 hash for afl"
     exit

zcutil/build-debian-package.sh

@@ -8,7 +8,7 @@ set -x
 
 BUILD_PATH="/tmp/zcbuild"
 PACKAGE_NAME="zcash"
-SRC_PATH=`pwd`
+SRC_PATH=$(pwd)
 SRC_DEB=$SRC_PATH/contrib/debian
 SRC_DOC=$SRC_PATH/doc