elf->data is 'signed char' and casting it to 'int' will sign extend.
Most non-intrusive fix is to just have get_elfeitype() take type as
'unsigned char' to make implicit cast.

diff -ru pax-utils-1.2.2.orig/paxelf.c pax-utils-1.2.2/paxelf.c
--- pax-utils-1.2.2.orig/paxelf.c	2017-01-24 20:24:53.000000000 +0000
+++ pax-utils-1.2.2/paxelf.c	2017-09-26 07:01:00.115498082 +0000
@@ -65,7 +65,7 @@
 	QUERY(ELFOSABI_STANDALONE),
 	{ 0, 0 }
 };
-const char *get_elfeitype(int ei_type, int type)
+const char *get_elfeitype(int ei_type, unsigned char type)
 {
 	switch (ei_type) {
 		case EI_CLASS:   return find_pairtype(elf_ei_class, type);
diff -ru pax-utils-1.2.2.orig/paxelf.h pax-utils-1.2.2/paxelf.h
--- pax-utils-1.2.2.orig/paxelf.h	2017-01-24 20:24:53.000000000 +0000
+++ pax-utils-1.2.2/paxelf.h	2017-09-26 07:00:44.941879820 +0000
@@ -56,7 +56,7 @@
 extern elfobj *_readelf(const char *filename, int read_only);
 #define readelf(filename) _readelf(filename, 1)
 extern void unreadelf(elfobj *elf);
-extern const char *get_elfeitype(int ei_type, int type);
+extern const char *get_elfeitype(int ei_type, unsigned char type);
 extern const char *get_elfetype(elfobj *elf);
 extern const char *get_endian(elfobj *elf);
 extern const char *get_elfosabi(elfobj *elf);