fix: improve version_compare logic

Coverity was warning about unreachable code because I forgot to put in
an if statement.

Signed-off-by: Terri Oda <terri@toybox.ca>

cve_bin_tool/version_compare.py

@@ -140,10 +140,14 @@ def version_compare(v1: str, v2: str):
                 # Honestly it's hard to guess if .dev3 is going to be more or less than .rc4
                 # unless you know the project, so hopefully people don't expect that kind of range
                 # matching
-                v1_newstring = re.sub("([a-zA-Z]+)([0-9]+)", r"\1.\2", v1_array[i])
-                v2_newstring = re.sub("([a-zA-Z]+)([0-9]+)", r"\1.\2", v2_array[i])
-                print(f"`{v1_newstring}` and `{v2_newstring}`")
-                return version_compare(v1_newstring, v2_newstring)
+                letter_number = re.compile("^[a-zA-Z]+[0-9]+$")
+                if re.match(letter_number, v1_array[i]) and re.match(
+                    letter_number, v2_array[i]
+                ):
+                    v1_newstring = re.sub("([a-zA-Z]+)([0-9]+)", r"\1.\2", v1_array[i])
+                    v2_newstring = re.sub("([a-zA-Z]+)([0-9]+)", r"\1.\2", v2_array[i])
+                    # print(f"`{v1_newstring}` and `{v2_newstring}`")
+                    return version_compare(v1_newstring, v2_newstring)
 
                 # And if all else fails, just compare the strings
                 if v1_array[i] > v2_array[i]: