unbreak some lines and fix some prototypes.

man/zip_file_extra_field_get.mdoc

diff --git a/man/zip_file_extra_field_get.mdoc b/man/zip_file_extra_field_get.mdoc
index c2cfdc9..a8c779a 100644
--- a/man/zip_file_extra_field_get.mdoc
+++ b/man/zip_file_extra_field_get.mdoc
@@ -41,13 +41,9 @@
 .Sh SYNOPSIS
 .In zip.h
 .Ft const zip_uint8_t *
-.Fn zip_file_extra_field_get "zip_t *archive" "zip_uint64_t index" \
-"zip_uint16_t extra_field_index" "zip_uint16_t *idp" "zip_uint16_t *lenp" \
-"zip_flags_t flags"
+.Fn zip_file_extra_field_get "zip_t *archive" "zip_uint64_t index" "zip_uint16_t extra_field_index" "zip_uint16_t *idp" "zip_uint16_t *lenp" "zip_flags_t flags"
 .Ft const zip_uint8_t *
-.Fn zip_file_extra_field_get_by_id "zip_t *archive" "zip_uint64_t index" \
-"zip_uint16_t extra_field_id" "zip_uint16_t extra_field_index" "zip_uint16_t *lenp" \
-"zip_flags_t flags"
+.Fn zip_file_extra_field_get_by_id "zip_t *archive" "zip_uint64_t index" "zip_uint16_t extra_field_id" "zip_uint16_t extra_field_index" "zip_uint16_t *lenp" "zip_flags_t flags"
 .Sh DESCRIPTION
 The
 .Fn zip_file_extra_field_get