Fix error messages.

* lisp/ob-coq.el (org-babel-coq-initiate-session):
* lisp/ob-latex.el (org-babel-execute:latex):
* lisp/org-macro.el (org-macro-replace-all):
* lisp/org.el (org--get-display-dpi): Fix formatting of error
messages.

lisp/ob-coq.el

@@ -69,7 +69,7 @@
 If there is not a current inferior-process-buffer in SESSION then
 create one.  Return the initialized session."
   (unless (fboundp 'run-coq)
-    (error "`run-coq' not defined, load coq-inferior.el."))
+    (error "`run-coq' not defined, load coq-inferior.el"))
   (save-window-excursion (run-coq "coqtop"))
   (sit-for 0.1)
   (get-buffer org-babel-coq-buffer))

lisp/ob-latex.el

@@ -176,14 +176,14 @@ This function is called by `org-babel-execute-src-block'."
 		  (shell-command (format "mv %s %s"
 					 (concat (file-name-sans-extension tex-file) "-1.svg")
 					 out-file)))
-	      (error "SVG file produced but HTML file requested.")))
+	      (error "SVG file produced but HTML file requested")))
 	   ((file-exists-p (concat (file-name-sans-extension tex-file) ".html"))
 	    (if (string-match "\\.html$" out-file)
 		(shell-command "mv %s %s"
 			       (concat (file-name-sans-extension tex-file)
 				       ".html")
 			       out-file)
-	      (error "HTML file produced but SVG file requested.")))))
+	      (error "HTML file produced but SVG file requested")))))
          ((string-match "\\.\\([^\\.]+\\)$" out-file)
           (error "Can not create %s files, please specify a .png or .pdf file or try the :imagemagick header argument"
 		 (match-string 1 out-file))))

lisp/org-macro.el

@@ -196,7 +196,7 @@ found in the buffer with no definition in TEMPLATES."
 		       ;; expansions.
 		       (save-excursion (insert value)))
 		      (finalize
-		       (error "Undefined Org macro: %s; aborting."
+		       (error "Undefined Org macro: %s; aborting"
 			      (org-element-property :key object))))))))))))
 
 (defun org-macro-escape-arguments (&rest args)

lisp/org.el

@@ -19014,7 +19014,7 @@ horizontal and vertical directions."
   (if (display-graphic-p)
       (round (/ (display-pixel-height)
 		(/ (display-mm-height) 25.4)))
-    (error "Attempt to calculate the dpi of a non-graphic display.")))
+    (error "Attempt to calculate the dpi of a non-graphic display")))
 
 ;; This function borrows from Ganesh Swami's latex2png.el
 (defun org-create-formula-image-with-dvipng (string tofile options buffer)