!4 fix build error

From: @ll3366 
Reviewed-by: @weidongkl 
Signed-off-by: @weidongkl

vamp-plugin-sdk.spec

@@ -1,6 +1,8 @@
+%define _smp_mflags -j6
+
 Name:           vamp-plugin-sdk
 Version:        2.5
-Release:        1
+Release:        2
 Summary:        An API for audio analysis and feature extraction plugins
 
 Group:          System Environment/Libraries
@@ -10,6 +12,7 @@ Source0:        http://code.soundsoftware.ac.uk/attachments/download/690/vamp-pl
 # https://sourceforge.net/tracker/?func=detail&aid=1884043&group_id=192001&atid=939644
 Patch0:         %{name}-2.5-libdir.patch
 
+BuildRequires:  gcc-c++
 BuildRequires:  libsndfile-devel
 #Requires:
 
@@ -46,7 +49,7 @@ sed -i 's|/lib/|/%{_lib}/|g' src/vamp-hostsdk/PluginLoader.cpp
 
 %build
 %configure
-make %{?_smp_mflags}
+%make_build
 
 
 %install
@@ -103,5 +106,8 @@ rm -rf $RPM_BUILD_ROOT
 
 
 %changelog
+* Fri Feb 11 2022 liweigang <liweiganga@uniontech.com> - 2.5-2
+- fix build error
+
 * Thu May 13 2021 He Rengui <herengui@uniontech.com> - 2.5-1
 - package init