Description of problem:
When I was trying to compile perf I was getting a build error due to a duplicate declaration of SLrline_get_update_client_data.  In order to get it to work correctly.

Version-Release number of selected component (if applicable):
Installed Packages
Name        : slang
Arch        : x86_64
Version     : 2.3.0
Release     : 1.fc22

Name        : slang-devel
Arch        : x86_64
Version     : 2.3.0
Release     : 1.fc22
Size        : 353 k


How reproducible:
Always

Steps to Reproduce:
1. Install slang and slang-devel
2. Attempt to build something that includes /usr/include/slang/slang.h
3. Build error should be immediate

Actual results:
The following build error
In file included from /usr/src/kernels/net-next/tools/perf/util/include/../../ui/libslang.h:12:0,
                 from /usr/src/kernels/net-next/tools/perf/util/include/../../ui/keysyms.h:4,
                 from /usr/src/kernels/net-next/tools/perf/util/include/../hist.h:305,
                 from /usr/src/kernels/net-next/tools/perf/util/include/../sort.h:23,
                 from ui/gtk/hists.c:4:
/usr/include/slang/slang.h:1634:15: error: redundant redeclaration of ‘SLrline_get_update_client_data’ [-Werror=redundant-decls]
 SL_EXTERN int SLrline_get_update_client_data (SLrline_Type *, VOID_STAR *);
               ^
  CC       fs/fs.o
/usr/include/slang/slang.h:1627:15: note: previous declaration of ‘SLrline_get_update_client_data’ was here
 SL_EXTERN int SLrline_get_update_client_data (SLrline_Type *, VOID_STAR *);
               ^
In file included from /usr/src/kernels/net-next/tools/perf/util/include/../../ui/libslang.h:12:0,
                 from /usr/src/kernels/net-next/tools/perf/util/include/../../ui/keysyms.h:4,
                 from /usr/src/kernels/net-next/tools/perf/util/include/../hist.h:305,
                 from /usr/src/kernels/net-next/tools/perf/util/include/../sort.h:23,
                 from ui/gtk/browser.c:4:
/usr/include/slang/slang.h:1634:15: error: redundant redeclaration of ‘SLrline_get_update_client_data’ [-Werror=redundant-decls]
 SL_EXTERN int SLrline_get_update_client_data (SLrline_Type *, VOID_STAR *);
               ^
/usr/include/slang/slang.h:1627:15: note: previous declaration of ‘SLrline_get_update_client_data’ was here
 SL_EXTERN int SLrline_get_update_client_data (SLrline_Type *, VOID_STAR *);
               ^


Expected results:
No build error

Additional info:
It looks like a patch may have already been submitted based on the one I found at:
http://lists.jedsoft.org/lists/slang-users/2015/0000000.html