fix computation of entry point and main app phdrs when invoking via ldso

entry point was wrong for PIE. e_entry was being treated as an
absolute value, whereas it's actually relative to the load address
(which is zero for non-PIE).

phdr pointer was wrong for non-PIE. e_phoff was being treated as
load-address-relative, whereas it's actually a file offset in the ELF
file. in any case, map_library was already computing it correctly, and
the incorrect code in __dynlink was overwriting it with junk.

src/ldso/dynlink.c

@@ -940,9 +940,7 @@ void *__dynlink(int argc, char **argv)
 		close(fd);
 		lib->name = ldname;
 		app->name = argv[0];
-		app->phnum = ehdr->e_phnum;
-		app->phdr = (void *)(app->base + ehdr->e_phoff);
-		aux[AT_ENTRY] = ehdr->e_entry;
+		aux[AT_ENTRY] = (size_t)app->base + ehdr->e_entry;
 	}
 	if (app->tls_size) {
 		app->tls_id = tls_cnt = 1;