removed unused file from 1988/spinellis

The `1988/spinellis/spinellis.data` file was an artifact
from the old 1988 Makefile.  It is not mentioned in the
`1988/spinellis/README.md`, nor is it needed.

1988/spinellis/Makefile

@@ -108,7 +108,7 @@ ENTRY= spinellis
 PROG= ${ENTRY}
 #
 OBJ= ${PROG}.o
-DATA= spinellis.data input.txt input2.txt
+DATA= input.txt input2.txt
 TARGET= ${PROG}
 #
 ALT_OBJ= ${PROG}.alt.o

1988/spinellis/spinellis.data

@@ -1,4 +0,0 @@
-main()
-{
-	printf("Hello world\n");
-}