cosmetics: Do not use braces in makefiles, use normal parentheses.

Originally committed as revision 9775 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -804,11 +804,11 @@ logfile="config.err"
 
 # installation paths
 PREFIX="/usr/local"
-libdir='${PREFIX}/lib'
+libdir='$(PREFIX)/lib'
 shlibdir="$libdir"
-incdir='${PREFIX}/include/ffmpeg'
+incdir='$(PREFIX)/include/ffmpeg'
-mandir='${PREFIX}/man'
+mandir='$(PREFIX)/man'
-bindir='${PREFIX}/bin'
+bindir='$(PREFIX)/bin'
 
 # toolchain
 cross_prefix=""
@@ -1852,7 +1852,7 @@ echo "/* Automatically generated by configure - do not modify! */" > $TMPH
 echo "#define FFMPEG_CONFIGURATION \"$FFMPEG_CONFIGURATION\"" >> $TMPH
 
 echo "PREFIX=$PREFIX" >> config.mak
-echo "prefix=\$(DESTDIR)\${PREFIX}" >> config.mak
+echo "prefix=\$(DESTDIR)\$(PREFIX)" >> config.mak
 echo "libdir=\$(DESTDIR)$libdir" >> config.mak
 echo "shlibdir=\$(DESTDIR)$shlibdir" >> config.mak
 echo "incdir=\$(DESTDIR)$incdir" >> config.mak