[SPARK-56027] Fix NoEmptyContinuation warning of spark-test-image/lint/Dockerfile

Author: dongjoon-hyun

dev/spark-test-image/lint/Dockerfile

@@ -66,7 +66,7 @@ RUN apt-get update && apt-get install -y \
 RUN Rscript -e "install.packages(c('devtools', 'knitr', 'markdown', 'rmarkdown', 'testthat', 'remotes'), repos='https://cloud.r-project.org/')" \
     && Rscript -e "devtools::install_version('pkgdown', version='2.0.1', repos='https://cloud.r-project.org')" \
     && Rscript -e "devtools::install_version('preferably', version='0.4', repos='https://cloud.r-project.org')" \
-    && Rscript -e "devtools::install_version('lintr', version='2.0.1', repos='https://cloud.r-project.org')" \
+    && Rscript -e "devtools::install_version('lintr', version='2.0.1', repos='https://cloud.r-project.org')"
 
 # See more in SPARK-39735
 ENV R_LIBS_SITE="/usr/local/lib/R/site-library:${R_LIBS_SITE}:/usr/lib/R/library"