[libgdata] build: Fix builddir != srcdir failure

[Emmanuele Bassi <ebassi src gnome org>]

commit fe8d0dd41823770c4283e7dbcc4b7ca1ad0d6eb9
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Sun Oct 4 14:08:49 2015 +0100

    build: Fix builddir != srcdir failure
    
    The split symbol files are in the srcdir path, not in the builddir one.

 Makefile.am |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index cb8d4e9..71f2371 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -535,11 +535,11 @@ gdata_libgdata_la_LDFLAGS = \
        $(AM_LDFLAGS)
 
 # Symbols file
-gdata/gdata.symbols: gdata/gdata-core.symbols gdata/gdata-goa.symbols
+gdata/gdata.symbols: $(top_srcdir)/gdata/gdata-core.symbols $(top_srcdir)/gdata/gdata-goa.symbols
 if ENABLE_GOA
-       $(AM_V_GEN)cat gdata/gdata-core.symbols gdata/gdata-goa.symbols > $@
+       $(AM_V_GEN)cat $(top_srcdir)/gdata/gdata-core.symbols $(top_srcdir)/gdata/gdata-goa.symbols > $@
 else
-       $(AM_V_GEN)cat gdata/gdata-core.symbols > $@
+       $(AM_V_GEN)cat $(top_srcdir)/gdata/gdata-core.symbols > $@
 endif
 
 EXTRA_gdata_libgdata_la_DEPENDENCIES = gdata/gdata.symbols