arg matches: raise postfix match length <5.4

When the string and file matches relied on byte for byte matching in
BPF, postfix matches were limited to 50 chars for >=5.4 and 40 chars
<5.4. With the new hash match look ups, the >=5.4 limit was raised to
the standard 128 characters by default. For <5.4, we can now raise the
'small program' limit to 96 without exceeding the instruction count.

Signed-off-by: Kevin Sheldrake <kevin.sheldrake@isovalent.com>

bpf/process/string_maps.h

@@ -170,7 +170,7 @@ struct {
 #ifdef __LARGE_BPF_PROG
 #define STRING_POSTFIX_MAX_MATCH_LENGTH STRING_POSTFIX_MAX_LENGTH
 #else
-#define STRING_POSTFIX_MAX_MATCH_LENGTH 40
+#define STRING_POSTFIX_MAX_MATCH_LENGTH 96
 #endif
 
 struct string_postfix_lpm_trie {