Use %setup+%autopatch instead of %autosetup -S git_am

When mtr is build inside git repo then build system includes git
revision into release number.

mtr.spec

@@ -3,7 +3,7 @@
 Summary: A network diagnostic tool
 Name: mtr
 Version: 0.87
-Release: 3%{?dist}
+Release: 4%{?dist}
 Epoch: 2
 Group: Applications/Internet
 License: GPLv2+
@@ -34,7 +34,8 @@ The mtr-gtk package provides the GTK+ interface for the mtr network
 diagnostic tool.
 
 %prep
-%autosetup -S git_am
+%setup -q
+%autopatch
 
 %build
 export CFLAGS="%{optflags} -fPIE"
@@ -80,6 +81,9 @@ desktop-file-install \
 %endif
 
 %changelog
+* Thu Mar  2 2017 Michal Sekletar <msekleta@redhat.com> - 2:0.87-4
+- Don't include git revision in version string
+
 * Wed Mar 01 2017 Michal Sekletar <msekleta@redhat.com> - 2:0.87-3
 - One more version bump for the same reason (hopefully last one)