fix DSO linking error in fedora and arch linux

to avoid this error

/usr/bin/ld: sensors-applet-plugins.o: undefined reference to symbol 'dlclose@@GLIBC_2.2.5'
/usr/bin/ld: note: 'dlclose@@GLIBC_2.2.5' is defined in DSO /lib64/libdl.so.2 so try adding it to the linker command line
/lib64/libdl.so.2: could not read symbols: Invalid operation
collect2: error: ld returned 1 exit status