Fix use of 'let -i' in scripts

Unlike "declare -i" and "local -i", the bash "let" does not support a
"-i" option. Rather, it takes it as a variable reference. If no "i"
variable is defined in scope, it does not cause an issue. If "i" has
been defined somewhere, however, it may cause a syntax issue, as the i
is evaluated.

A recent update to build-stx-images.sh added a loop that defines an
"i" variable without limiting its scope. In a current image build,
this loop ends with having "i" defined as a URL. As a result, a
"syntax error in expression" occurs, causing the "with_retries"
function to fail to increment the counter. Should a build error occur,
the "with_retries" will never hit the retry limit, looping until it
has a successful result.

This update removes the -i from all "let -i" occurrences in the build
scripts.

Change-Id: I34ad49f8872a81659ff4caf8087b256ea9fb3d32
Closes-Bug: 1891189
Signed-off-by: Don Penney <don.penney@windriver.com>
(cherry picked from commit f36db7e207)

build-tools/build-wheels/docker/docker-build-wheel.sh

@@ -117,7 +117,7 @@ function with_retries {
     local -i attempt=0
 
     while :; do
-        let -i attempt++
+        let attempt++
 
         echo "Running: ${cmd} $@"
         ${cmd} "$@"
@@ -340,7 +340,7 @@ from_zip
 from_pypi
 
 if [ -f $FAILED_LOG ]; then
-    let -i failures=$(cat $FAILED_LOG | wc -l)
+    let failures=$(cat $FAILED_LOG | wc -l)
 
     cat <<EOF
 ############################################################

build-tools/build-wheels/utils.sh

@@ -21,7 +21,7 @@ function with_retries {
     local -i attempt=0
 
     while :; do
-        let -i attempt++
+        let attempt++
 
         echo "Running: ${cmd} $@"
         ${cmd} "$@"

build-tools/patch-iso

@@ -148,7 +148,7 @@ function check_requirements {
         which ${req} >&/dev/null
         if [ $? -ne 0 ]; then
             echo "Unable to find required utility: ${req}" >&2
-            let -i missing++
+            let missing++
         fi
     done
 

build-tools/srpm-utils

@@ -206,7 +206,7 @@ srpm_create_raw_extract_script () {
       SAME=1
    fi
 
-   let -i COUNT=0
+   let COUNT=0
    while [ $SAME -eq 0 ]; do
       \cp -f $STDOUT_LOG $PREV_STDOUT_LOG
       \cp -f $STDERR_LOG $PREV_STDERR_LOG
@@ -226,7 +226,7 @@ srpm_create_raw_extract_script () {
       if [ $? -eq 0 ]; then
          SAME=1
       fi
-      let -i COUNT++
+      let COUNT++
       if [ $COUNT -ge 20 ]; then 
          break; 
       fi