Bash - Suppressing output to STDOUT
Turns out the xpath=( xcode-select --print-path ) line in the if statement of the original function was the problem.  Additionally, once I got the error message suppressed, I noticed there was an unnecessary stdout message, so I decided to suppress that as well.

I was able to suppress the stderror and stdout messages by changing the function to the following:

function check_clt() {
    if type xcode-select &gt;/dev/null 2&gt;&amp;1 &gt;&amp;- &amp;&amp; xcode-select -p &gt;/dev/null 2&gt;&amp;1 &amp;&amp; test -d $(xcode-select -p) &gt;/dev/null 2&gt;&amp;1 &amp;&amp; test -x $(xcode-select -p) &gt;/dev/null 2&gt;&amp;1; then
        echo ""
        echo "The required Xcode command-line-tools are already installed! Moving on!"
        sleep 3
    else
        instructions
        sleep 45
        xcode-select --install
    fi
}