BUILD/MINOR: regex: avoid a build warning on USE_PCRE2 with -Wundef

regex-t emits a warning on #elif USE_PCRE2 when built with -Wundef,
let's just fix it. This was reported in GH issue #1369.

diff --git a/include/haproxy/regex-t.h b/include/haproxy/regex-t.h
index ff415e8e165c1749860eedaf7c421a296da5879a..33d88a2eaf719b68baf101e363b3fb60e19c3e42 100644 (file)
--- a/include/haproxy/regex-t.h
+++ b/include/haproxy/regex-t.h
@@ -36,7 +36,7 @@
 #define PCRE_STUDY_JIT_COMPILE 0
 #endif
 
-#elif USE_PCRE2
+#elif defined(USE_PCRE2)
 #include <pcre2.h>
 #include <pcre2posix.h>
 
@@ -53,7 +53,7 @@ struct my_regex {
 #error "The PCRE lib doesn't support JIT. Change your lib, or remove the option USE_PCRE_JIT."
 #endif
 #endif
-#elif USE_PCRE2
+#elif defined(USE_PCRE2)
        int(*mfn)(const pcre2_code *, PCRE2_SPTR, PCRE2_SIZE, PCRE2_SIZE, uint32_t, pcre2_match_data *, pcre2_match_context *);
        pcre2_code *reg;
 #else /* no PCRE */