Removed useless line from make rules.

docs/rules.mk

 report=report
 
+.PHONY: docs
+
 docs: $(b)proposal.pdf $(b)presentation.pdf $(b)$(report).pdf $(b)$(report).bbl
 
 $(b)%.pdf: $(d)%.tex
@@ -9,7 +11,6 @@ $(b)%.pdf: $(d)%.tex
 		-output-directory "../`dirname $@`" `basename $^`
 
 $(b)$(report).bbl: $(d)$(report).bib
-	mkdir -p `dirname $@`
 	cp $(d)$(report).bib $(b)$(report).bib
 	cd $(b); bibtex8 $(report).aux
 	cd $(d); \
@@ -17,5 +18,3 @@ $(b)$(report).bbl: $(d)$(report).bib
 		-output-directory "../`dirname $@`" $(report).tex; \
 	pdflatex -halt-on-error -interaction=nonstopmode \
 		-output-directory "../`dirname $@`" $(report).tex
-
-.PHONY: docs